Light distribution controllers are known which automatically adjust light distribution of a headlight of a vehicle in accordance with, for example, an angle of turn, the vehicle speed, or the presence or absence of an oncoming car (for example, see Japanese Patent No. 3747738 and Japanese Unexamined Utility Model Registration Application Publication No. 60-61942).
Examples of a known specific structure for controlling light distribution of a headlight of a vehicle include a structure for adjusting the angle and the forward-backward direction position of a concave reflecting mirror in a headlight and a structure for adjusting relative positions of the condenser lens and the diffusion lens which are disposed in front of the light source in a headlight (for example, see Japanese Patent No. 3747738, Japanese Unexamined Utility Model Registration Application Publication No. 60-61942, and Japanese Examined Utility Model Registration Application Publication No. 8-6326).
A light distribution controller is known which, upon detection of a pedestrian, controls the light quantity and the direction of illumination light which is emitted from a headlight to the pedestrian in order to prevent the pedestrian from being dazzled by the glare due to the light from the headlights of a vehicle (for example, see Japanese Patent No. 4178644).
A light distribution controller is known which controls a warning to a driver in accordance with an area in which a pedestrian is present and which is one of multiple areas obtained by dividing an area ahead of a vehicle (for example, see Japanese Patent No. 3515926).
A light distribution controller of the related art (for example, see Japanese Patent No. 4178644) starts restricting illumination of a pedestrian upon detection of the pedestrian. Therefore, there is an advantage for a pedestrian in that the dazzling illumination from a vehicle is immediately avoided. In contrast, there is a disadvantage for a driver to recognize the pedestrian because of a reduced time period in which the pedestrian is illuminated.